Caption: Crick and Watson.The discoverers of the structure of DNA. James Watson (b.1928) at right and Francis Crick (1916-2004), shortly after working out the structure of the DNA molecule in 1953. Crick and Watson met at the Cavendish Laboratory, Cambridge, in 1951. Their work on DNA was performed with a knowledge of Chargaff's ratios of the bases in DNA and some access to the X-ray crystallography of Maurice Wilkins and Rosa- lind Franklin at King's College London. Combining all of this work led to the deduction that DNA exists as a double helix. Crick, Watson & Wilkins shared the 1962 Nobel Prize for Physiology or Medicine, Franklin having died in 1958.